package de.fub.bytecode.classfile;

import  de.fub.bytecode.Constants;
import  java.io.*;

/**
 * This class is derived from <em>Attribute</em> and declares this class
 * as `synthetic', i.e. it needs special handling.
 * It is instantiated from the <em>Attribute.readAttribute()</em> method.
 *
 * @version $Id: Synthetic.java,v 1.1.1.1 2000/08/10 16:05:07 cvs Exp $
 * @author  <A HREF="http://www.inf.fu-berlin.de/~dahm">M. Dahm</A>
 * @see     Attribute
 */
public final class Synthetic extends Attribute {
  private byte[] bytes;

  /**
   * @param name_index Index in constant pool to CONSTANT_Utf8
   * @param length Content length in bytes
   * @param bytes Attribute contents
   * @param constant_pool Array of constants
   * @param sourcefile_index Index in constant pool to CONSTANT_Utf8
   */
  public Synthetic(int name_index, int length, byte[] bytes,
		   ConstantPool constant_pool)
  {
	super(ATTR_SYNTHETIC, name_index, length, constant_pool);
	this.bytes         = bytes;
  }  
  /**
   * Construct object from file stream.
   * @param name_index Index in constant pool to CONSTANT_Utf8
   * @param length Content length in bytes
   * @param file Input stream
   * @param constant_pool Array of constants
   * @throw IOException
   */
  Synthetic(int name_index, int length, DataInputStream file,
	    ConstantPool constant_pool) throws IOException
  {
	this(name_index, length, (byte [])null, constant_pool);

	if(length > 0) {
	  bytes = new byte[length];
	  file.readFully(bytes);
	  System.err.println("Synthetic attribute with length > 0");
	}
  }  
  /**
   * Initialize from another object. Note that both objects use the same
   * references (shallow copy). Use clone() for a physical copy.
   */
  public Synthetic(Synthetic c) {
	this(c.getNameIndex(), c.getLength(), c.getBytes(), c.getConstantPool());
  }  
  /**
   * Called by objects that are traversing the nodes of the tree implicitely
   * defined by the contents of a Java class. I.e., the hierarchy of methods,
   * fields, attributes, etc. spawns a tree of objects.
   *
   * @param v Visitor object
   */
  public void accept(Visitor v) {
	v.visitSynthetic(this);
  }  
  /**
   * @return deep copy of this attribute
   */
  public Attribute copy(ConstantPool constant_pool) {
	Synthetic c = (Synthetic)clone();

	if(bytes != null)
	  c.bytes = (byte[])bytes.clone();

	c.constant_pool = constant_pool;
	return c;
  }  
  /**
   * Dump source file attribute to file stream in binary format.
   *
   * @param file Output file stream
   * @throw IOException
   */ 
  public final void dump(DataOutputStream file) throws IOException
  {
	super.dump(file);
	if(length > 0)
	  file.write(bytes, 0, length);
  }  
  /**
   * @return data bytes.
   */  
  public final byte[] getBytes() { return bytes; }  
  /**
   * @param bytes.
   */
  public final void setBytes(byte[] bytes) {
	this.bytes = bytes;
  }  
  /**
   * @return String representation.
   */ 
  public final String toString() {
	StringBuffer buf = new StringBuffer("Synthetic");

	if(length > 0)
	  buf.append(" " + Utility.toHexString(bytes));

	return buf.toString();
  }  
}